Tracker-board.



F. L. McCORMICK.

TRACKER BOARD.

APPLICATION FILED JULY23. 1914.

Patented Nov. 21, 1916.

INVENTBR @m XZWW, bY 4 11 ATTUR ru UNITED STATES PATENT OFFICE.

FRANK L. MCCORMICK, OF NORTH TONAWANDA, NEW YORK, ASSIGNOR TO THE RUDOLPH WURLITZER MANUFACTURING COMPANY, OF NORTH TONAWANDA, NEW YORK, A CORPORATION OF NEVJ YORK.

TRACKER-BOARD.

Application filed July 23, 1914.

To all whom it may concern Be it known that I, FRANK L. MCCOR- MICK, a citizen of the United States, residing at North Tonawanda, in the county of Niagara and State of New York, have in vented new and useful Improvements in Tracker-Boards, of which the following is a specification.

It is customary to extend a comparatively fine screen of woven wire across the ducts of tracker-boards to intercept dust, lint and particles of paper detached from the music sheets passing over the trackers, in order to prevent such substances from interfering with the operation of the valves or other parts of the usual pneumatic actions which are controlled by the tracker boards and music rolls. For this purpose the tracker board is usually divided into separable sections between which the screen is interposed and from which it may be removed from time to time for cleaning it, as required. As heretofore constructed, such screens become clogged in a comparatively short time and require frequent cleaning.

The object of my invention is to so construct the tracker board that it will clog less rapidly and therefore require less frequent cleaning.

In the accompanying drawings: Figure 1 is a transverse section of a tracker board embodying the invention. Fig. 2 is an enlarged fragmentary section thereof, on line 22, Fig. 1. Fig. 3 is a longitudinal section on line 33, Fig. 2, the scale being exag gerat'ed for clearness.

Similar characters of reference indicate corresponding parts in the several views.

1 indicates the rear or base-section ofthe tracker and 2 the front or face-section, which is removably attached to the rear section by any suitable means. The preferred fastenings are the customary hooks located at opposite ends of the board, one of them being shown at 3, in Fig. 3.

4 indicates the portions of the trackerducts or tubes formed in the front section, and 5 the continuation thereof formed in the rear section. '1

Removably arranged between the tracker sections is the dust-screen 6 of fine wire cloth or other suitable material. In the construction shown, this screen is interposed be- Specification of Letters Patent.

Patented Nov. 21, 1916.

Serial No. 852,597.

&c., drawn into the mouths of its ducts is first deposited upon the central portion of the screenarea belonging to each duct and then gradually upon the marginal portion of that area opposite the enlargements 8. In ordinary trackers, the screen must be removed and cleaned when the dust, &c., in the course of time covers areas corresponding to the diameter of the ducts. In a tracker em bodying this improvement, even when the screen becomes clogged to the extent just mentioned, there still remains a considerable open or unclogged portion for the passage of the air equal. to the difference in cross sectional area between the ducts and the enlargements 8, and. the tracker board can therefore continue in service for a cone spondingly longer period before requiring the screen to be cleaned.

While affording this important advantage, the improvement is exceedingly simple and its cost is but nominal.

My invention is herein shown as applied to a tracker board, but it is also applicable to other duct-boards having one or more air passages provided with a dust screen.

I claim as my invention:

1. A tracker or the like having a duct and a dust-screen extending across the duct, the duct being provided with an enlargement adjacent to both sides of the screen and the walls of said enlargements which face the sides of the screen being both spaced therefrom.

2. A tracker divided transversely of its ducts and having a screen removably interposed between its sections, the opposing ends of corresponding duct-sections being provided with enlargements and the walls of said enlargements which face the sides of both sides of the screen from the opposing 10 the screen being both spaced therefrom. faces of the tracker-sections.

3. The combination of a tracker divided \Vitness my hand this 6th day of July, transversely of its ducts, layers arranged be- 1914.

5 tween the sections of the tracker and having 7 registering openings which coincide with the FRANK MCCORMICK tracker-ducts but are of larger dimensions Vitnesses: than the ducts, and a screen interposed be- Trros. B. GRAY, tween said layers, said layers separating FRANCIS PRUMEAU.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, I). G. 

